What is the initial treatment for IgG4 (Immunoglobulin G4) pancreatitis?

From the Guidelines

The initial treatment for IgG4 pancreatitis is oral glucocorticoids, typically prednisone starting at 0.6-0.8 mg/kg daily (usually 40 mg daily) for the first 4 weeks, as recommended by the most recent guidelines 1. This approach is supported by the EASL clinical practice guidelines on sclerosing cholangitis, which suggest that starting doses of 40 mg daily or 0.6-0.8 mg/kg daily for the first 4 weeks have been widely recommended in Japanese, American, and European Guidelines 1. Some key points to consider when initiating treatment with prednisone include:

• Monitoring for steroid-related side effects such as hyperglycemia, weight gain, and osteoporosis
• Obtaining baseline laboratory tests including liver function, complete blood count, and blood glucose levels
• Considering alternative therapies such as rituximab for patients with contraindications to steroids or those who relapse after steroid treatment
• Maintenance therapy with low-dose steroids (2.5-10 mg/day) or immunomodulators like azathioprine may be necessary for patients with recurrent disease after initial treatment 1. It's essential to note that the British Society of Gastroenterology and UK-PSC guidelines for the diagnosis and management of primary sclerosing cholangitis also recommend corticosteroids as first-line treatment for IgG4-SC, with a common regimen being oral prednisolone 40 mg daily for 2–4 weeks, subsequently reduced by 5 mg every week over approximately 8–12 weeks 1. However, the most recent and highest quality study, the EASL clinical practice guidelines on sclerosing cholangitis, should be prioritized when making a definitive recommendation 1.

From the Research

Initial Treatment for IgG4 Pancreatitis

The initial treatment for IgG4 pancreatitis, also known as autoimmune pancreatitis (AIP), typically involves the use of corticosteroids.

• The standard treatment includes oral prednisolone at an initial dose of 30-40 mg/day 2, 3, 4.
• This treatment approach is based on the fact that AIP responds well to corticosteroids, with most patients experiencing significant improvement in symptoms and laboratory tests 2, 3.
• The treatment regimen may vary depending on the patient's response and the presence of extrapancreatic manifestations, such as bile duct stenosis or sclerosing cholangitis 2, 5.

Steroid Therapy and Maintenance

• Steroid therapy is usually continued for a period of time to maintain remission, with the dose gradually tapered down 2, 3.
• In some cases, maintenance therapy may be required to prevent relapse, especially in patients with incomplete morphological and serological resolution 2.
• Alternative treatments, such as mycophenolate mofetil or rituximab, may be considered for patients who are steroid-dependent or experience relapse 5, 6, 4.

Treatment Outcomes and Relapse

• The remission rate after initial treatment with steroids is generally high, ranging from 85% to 96% 3.
• However, relapse rates are also high, and treatment of relapsed disease remains experimental 6.
• Close monitoring and adjustment of treatment regimens are necessary to manage relapses and maintain long-term remission 2, 3, 4.